Dongjiang Water

The local yield is inadequate to meet the fresh water demand in Hong Kong. It also fluctuates significantly and is unreliable, the difference in the quantities of local yield could be up to 200 million cubic metres. Confronted with the challenge of inadequate and unreliable local yield, Hong Kong has been importing Dongjiang (DJ) water since 1965 to meet local water demand.

In the Mainland

Dongjiang is one of the three tributaries of the Pearl River. Its sources are located at the Xunwu, Anyuan and Dingnan counties of Jiangxi Province and flows from northeast to southwest direction into Guangdong Province. It supplies fresh water for a total of more than 40 million people in Heyuan, Huizhou, Dongguan, Guangzhou, Shenzhen and Hong Kong. DJ water supplied to Hong Kong is originally extracted from Taiyuan Pumping Station at Dongguan and conveyed over a dedicated adequate. It eventually discharges into the Shenzhen Reservoir before being fed by pipelines across the border to Muk Wu Raw Water Pumping Station of Hong Kong.

Subsequent to the commissioning of the dedicated aqueduct system in June 2003, the DJ water supply route is now segregated from all pollution sources along the Shima River.

In Hong Kong

DJ water, after received at Muk Wu, is then delivered along the following three major aqueduct systems for transfer to territory-wide storage and treatment facilities:

Western Route to Ngau Tam Mei and Au Tau Water Treatment Works and via Au Tau Raw Water Pumping Station to Tai Lam Chung Reservoir;

Central Route to Yau Kom Tau Water Treatment Works and via Tau Pass Culvert to Tai Po Tau Raw Water Pumping Stations, and thence to Tai Po and Sha Tin Water Treatment Works or Plover Cove Reservoir; and

Eastern Route via Nam Chung Aqueduct to Plover Cove Reservoir, and thence to High Island Reservoir or Ma On Shan and Pak Kong Water Treatment Works via Harbour Island Raw Water Pumping Station, Tolo Channel Aqueduct, Sai O Raw Water Pumping Station and High Island Tunnels.

These three routes are inter-connected through the Tai Po Tau Raw Water Pumping Station complex to provide maximum flexibility in system operation throughout the year; this is particularly crucial during the annual Dongjiang water shutdown period in December when flow from Plover Cove Reservoir and High Island Reservoir is required to maintain the necessary throughput at the treatment works in Sha Tin and other parts of the territory.

As early as in 1960, the Hong Kong Government was well aware that the increasing fresh water demand in Hong Kong could no longer be satisfied by local yield solely, and the procurement of fresh water from Guangdong Province was the most efficient way for fulfilling the unmet water needs. On 15 November 1960, the Governments of Guangdong Province and Hong Kong reached an agreement on importing 22.7 million cubic metres per year of raw water from the Shenzhen Reservoir to Hong Kong every year.

In 1963, the Governments of Guangdong Province and Hong Kong held several rounds of discussions and reached a consensus on the implementation of the Dongjiang-Shenzhen Water Supply Scheme. The Scheme was approved by Prime Minister Zhou Enlai and granted a special fund by the Central People’s Government for its construction works at the end of the year. Meanwhile, large-scale pumping stations, pipelines and tunnels were constructed in Hong Kong to facilitate the distribution of DJ water to various districts over the territory.

Hong Kong has enjoyed 24-hour uninterrupted water supply since 1982. This is achieved through the Agreement for the supply of Dongjiang water to Hong Kong (Supply Agreement) with the Government of Guangdong Province. The first Supply Agreement was signed in 1960 and up to 2017, eleven Supply Agreements had been signed. All Supply Agreements were based on consumption projections in Hong Kong. These projections took into account population growth, industry and commercial demands and predictions on local yields from Hong Kong’s gathering grounds.

DJ is not only the major source of fresh water for Guangzhou, Shenzhen, Dongguan, Huizhou, Heyuan, but also has the important task of supplying water to Hong Kong, serving a total population of over 40 million. With average annual per capita water resources of only 1 100 cubic metres, the DJ river basin is regarded as an area of water scarcity according to international assessment standards. Therefore, Guangdong Province implemented a DJ River Basin Water Resources Allocation Scheme, which co-ordinates the annual flow in the river basin according to the total amount of allocated water resources, so as to ensure a reasonable and efficient usage of the limited water resources. In addition, the water resource utilisation rate of the DJ has already reached a level very close to its exploitation limit, indicating a fairly tight supply of water resources.

Besides, the local yield is inadequate to meet the fresh water demand in Hong Kong. It also fluctuates significantly and is unreliable. In order to safeguard our water security, the “package deal lump sum” approach is adopted in the DJ water supply agreement which secures a water right in the form of an annual ceiling of supply quantity with a view to maintaining water supply round-the-clock even under the extreme drought condition with a return period of 1 in 100 years.

Hong Kong and Guangdong (GD) are under the same climatic setting (rainfall pattern, temperature, etc.). When our local yield reduces during drought years, the quantity of DJ water available for distribution will also dwindle. In previous negotiation, we had explored other payment approach like the “payment on actual supply quantity” approach with the GD side and they expressed difficulty to guarantee that the water supply quantity requested by Hong Kong can be met particularly in drought years given the keen demand for the limited DJ water resources. We will be exposed to a risk of inadequate water supply to Hong Kong during drought years unless we set a “reserved quantity” for possible need during drought years in the DJ water supply agreement and pay for it. However, such arrangement is effectively the same as the “package deal lump sum” approach we have adopted for the DJ water supply agreements since 2006. In any case, in the negotiation for a new agreement, we will further explore with the GD side the viability of flexible payment approach based on water consumption.

"Package Deal Lump Sum" Approach

Under the "package deal lump sum" approach, Hong Kong is assured of an adequate DJ water supply up to the annual supply ceiling in the agreements. We would inform the GD side the DJ water supply quantity on a monthly basis, thereby achieving a better control of the storage level in Hong Kong, minimizing water overflow (Fresh water overflow at the reservoirs does not involve DJ water; for details please refer to reservoir overflows.) and saving pumping costs. In addition, the annual supply ceiling is obtained on the basis of a detailed analysis taking into account the forecast fresh water demand and local yield to ensure 99% reliability of water supply during the agreement periods.

If the annual supply ceiling is lowered, Hong Kong will be exposed to a risk of inadequate water supply in the event of drought. For instance, we imported DJ water close to the ceiling in 2011 as the rainfall in that year fell short of the normal level by 40%. If the annual supply ceiling of 820 million cubic metres had been lowered, Hong Kong might have inadequate fresh water supply in 2011 and might need to impose water rationing.

The current DJ water supply agreement is for a 3-year period (2018 to 2020).

National Water Standard

Under the current DJ water supply agreement, the Guangdong authorities would maintain the quality of the DJ water supplied to Hong Kong to meet the national standard set out for Type II waters (applicable to the abstraction for human consumption in first class protection area) in the “Environmental Quality Standards for Surface Water GB3838-2002”. The Government of the Hong Kong Special Administrative Region has all along been maintaining close liaison with the Guangdong authorities on the water quality of the DJ water supplied to Hong Kong through an established institutional mechanism, which includes the Guangdong/Hong Kong Water Supply Business Meeting, Guangdong/Hong Kong Water Supply Operation and Management Technical Cooperation Sub-group Meeting, and the Special Panel on the Protection of DJ Water Quality.

The Guangdong authorities have adopted the following measures to prevent contamination of DJ water supplied to Hong Kong:

Relocation of the intake point upstream: In 1998, the intake point of DJ water was relocated upstream to a location of better water quality.

Bio-nitrification Plant: To enhance water quality, a bio-nitrification plant at the Shenzhen Reservoir was commissioned in early 1999.

Shima River Sewage Diversion Works: The Shima River Sewage Diversion Works was completed in 2005. By making use of a rubber dam, contaminated water from Shima River is deterred from flowing into Dongjiang near the intake point at the Taiyuan Pumping Station. This can further safeguard the quality of the DJ water supplied to Hong Kong.

Comprehensive remediation project at the Sha Wan River Basin: A comprehensive remediation project of the water environment of the Sha Wan River Basin was launched in late 2016 to reduce the risk of Shenzhen Reservoir being polluted by flood discharge from the Sha Wan River in order to protect the water quality of the Shenzhen Reservoir. The project is expected to be completed in 2019.

Water Quality Monitoring

The WSD has installed a 24-hour on-line monitoring system at the reception point of the Muk Wu Raw Water Pumping Station to closely monitor the quality of the DJ water supplied to Hong Kong. Regular water samples are also collected at Muk Wu Raw Water Pumping Station for detailed analysis to ensure that the DJ water supplied to Hong Kong complies with the required standards. The WSD would adjust the water treatment processes at water treatment works according to the water quality of the DJ water supplied to Hong Kong so as to ensure that the treated water quality complies with the Hong Kong Drinking Water Standards and the water is safe for consumption.

In case of any anomaly in the quality of DJ water, WSD will immediately take contingency measures, including strengthening the monitoring of various water quality parameters at Muk Wu Raw Water Pumping Station, and liaise with the Guangdong authorities concerned to decide if reduction or suspension of the DJ water supply is required in the light of its actual quality conditions.

Information about the quality of the DJ Water supplied to Hong Kong

Water Quality of Dongjiang’s Main Stream in 2017 as Monitored at the East Bank Section

Based on the water quality monitoring results, the Department of Ecology and Environment of Guangdong Province has been regularly providing the water quality data of samples taken from the intake of DJ water at the Taiyuan Pumping Station which locates at the East Bank Section of Dongjiang's upper main stream. The data in 2017 is as follows:

For further information on DJ water quality, please visit the homepage of the Department of Ecology and Environment of Guangdong Province at www.gdep.gov.cn.

DJ Water Quality for the Period of October 2017 - September 2018 as received at the Muk Wu Raw Water Pumping Station in Hong Kong

The quality of DJ Water supplied to Hong Kong for this period complied with the national standard set out for Type II waters (applicable to the abstraction for human consumption in first class protection area) in the “Environmental Quality Standards for Surface Water (GB3838-2002)”. For details please refer to:

The DJ water supply agreement stipulates the following three factors in consideration of adjusting the price of DJ water:

Changes in relevant price indices of GD and Hong Kong;

Changes in RMB/HKD exchange rates; and

Changes in operating costs.

Under this mechanism, the prices of DJ water are allowed to rise or fall. In fact, both GD and Hong Kong agreed in 2006 on lowering the prices of DJ water based on the aforementioned factors. Setting aside the changes in RMB/HKD exchange rates, the prices of DJ water in the past decade only increased by 3.7% per year, similar to the average annual rate of change of the relevant price indices of the two sides.

When negotiating over the current DJ water supply agreement (from 2018 to 2020) in 2017, it was noted that the average annual rate of change in RMB/HKD exchange rate was about -2.29% in the previous three years (from 2014 to 2016). Besides, the average annual rate of change in the relevant price indices of GD and Hong Kong was about +2.66% over the same period. After rounds of negotiation, the GD side agreed the annual supply ceiling to be 820 million cubic metres, and the respective expenditures on purchasing DJ water are shown in the following table:

Year

Expenditure(HK$ million)

Change

Average unit cost(HK$/m3)

2018

4,792.59

+0.3%

5.8

2019

4,807.00

+0.3%

5.9

2020

4,821.41

+0.3%

5.9

Taking account of the actual rates of change of RMB/HKD exchange rate and the relevant price indices of GD and Hong Kong during 2014 to 2016, we consider the adjustments in water price reasonable.

The Advisory Committee on Water Supplies (Advisory Committee) is an independent body comprising members from the public including academics, district councilors, green advocates, professionals, trades and officials from related government departments and bureau.

Visit to the DJ Water Supply System has been conducted annually by the members of the Advisory Committee. Through the annual visits, members can be updated on the work in protection of DJ water quality by the GD authorities and have the opportunity of direct dialogue with their officials on DJ water quality.

A delegation of the Legislative Council (LegCo) Panel on Development conducted a two-day duty visit from 14 to 15 April 2017 to the Dongjiang River Basin in Guangdong Province.

The purpose of the duty visit is for Members to learn about the operation of the Dongjiang-Shenzhen Water Supply System as well as measures taken by the GD authorities in safeguarding the quality of DJ water supplied to Hong Kong. In addition, Members made use of the opportunity to exchange views with the GD authorities on issues of mutual concern related to the supply of DJ water to Hong Kong.